Hi Guys n Gals,
I have found some seemingly strange behavior that may
be of interest to this list.
My assumption was that the \b pattern in a regex would
always match the beginning and end of a string (as
documented in the perlre page). However on my build of
5.8.7 this is not the case if the character being
matched at the beginning or the end is a
"meta-character" ie. quotemeta would escape it. Also
note that escaping the charcter doesn't seem to make a
difference.
Here are some more examples, run in `perl -d -e 1`:
DB<26> p '/' =~ m"\/\b";
DB<27> p '/' =~ m"\/";
1
DB<28> p 'a' =~ m"a\b";
1
DB<29> p 'a' =~ m"\ba\b";
1
DB<32> p '/' =~ m"\/\b";
DB<33> p '/' =~ m"/\b";
DB<34> p '/' =~ m"/";
1
DB<35> p 'a/' =~ m"a/";
1
DB<36> p 'a/' =~ m"a/\b";
DB<37> p 'a/' =~ m"\ba/";
1
DB<39> p '/' =~ m"^/";
1
DB<40> p 'a/b' =~ m"\b/";
1
DB<41> p '/' =~ m"\b/";
DB<42> p '//' =~ m"\b/";
DB<43> p '//' =~ m"\b|\W/";
1
DB<44> p '/' =~ m"\b|\W/";
DB<45> p '/' =~ m"^|\b|\W/";
1
DB<46> p '/' =~ m"\b|\W|^/";
1
Maybe this is not a bug, and this is just another
nuance of regexs' that I have not learned, but it
looks very fishy.
Any thoughts/wisdom?
Thanks!
-Carl
_______________________________________________
Boston-pm mailing list
[email protected]
http://mail.pm.org/mailman/listinfo/boston-pm
